In the squad of 35, 19 are from Glasgow Warriors, the side who are currently second in the RaboDirect PRO12 and Johnson admits he is happy to put his faith in youth.

“We’ve chosen this squad with two parameters uppermost in our minds: current form and looking to the future,” he said.

“Where two players have been vying for the one spot in areas such as the back-row, we’ve gone with the form option.

“I’ve been impressed with a number of the young fellows who’ve helped Glasgow to second place in the Rabo, especially by their work ethic and determination to improve.

“This squad is for our training camp in Glasgow next week and we still have the option to add to it for the Six Nations.”

Perpignan’s Alasdair Strokosch will miss the camp for family reasons as his wife is expecting their second child while Chris Cusiter, Nick De Luca, John Barclay, Ross Rennie, Scott Lawson and Jon Welsh are all invited to continue their recovery from injury with the main squad.

There are recalls for No.8 Johnnie Beattie, who missed out on selection for the 2011 Rugby World Cup, and Richie Vernon, Alasdair Dickinson, Moray Low, Robert Harley and Duncan Weir who were not involved during the autumn.